DR is an alternative to x-ray imaging technologies that rely on photosensitive film layers to capture radiation exposure and thus to produce and store an image of a subject's internal physical features. With digital radiography, the radiation exposure energy captured on radiation sensitive layers of a digital x-ray detector is converted, pixel by pixel, to electronic image data which is then stored in memory circuitry for subsequent read-out and display on suitable electronic image display devices. One of the driving forces in the success of digital radiography is the ability to rapidly visualize and communicate stored images via data networks to one or more remote locations for analysis and diagnosis by the radiologist, without the delay that results when film must be developed and checked, then packaged and mailed or sent by courier to a remote location.
DR is viewed as having some advantages over conventional film-based and earlier computed radiography (CR) systems. For example, DR provides the ability to obtain radiographic image data without the need to move, handle, process, or scan any type of imaging medium following exposure. Data downloaded directly from the DR receiver panel is then available for viewing and diagnosis on-site or at any appropriately networked viewer workstation.
Improvements in performance, miniaturization, and packaging have enabled the development of a portable DR receiver panel that is battery-powered and capable of wireless communication for control signals and image data. Among other advantages, this provides a DR receiver panel having a low-profile design that can be compatible with receiver dimensions used for earlier film and CR systems.
While DR imaging systems have advantages over earlier film and CR systems, replacing such a earlier x-ray system can be very costly, thereby limiting the availability of DR systems as hospitals attempt to maximize their investment in older equipment and to extend its usable lifetime.
To meet the need for the improved capabilities offered by DR imaging, a number of companies that provide x-ray equipment offer retrofit configurations that allow a DR receiver panel to be used with existing x-ray components, in place of a film or CR cassette. Existing retrofit solutions, however, have one or more limitations, in that they:
(a) do not allow use of both earlier types of receivers and the newer DR panels. A retrofit that completely converts existing hardware to DR use but prevents the use of film or CR receivers is less desirable, since both film and CR media have particular strengths and may still be preferred in some types of imaging situations. There would be advantages to a retrofit solution that retains the ability to use the imaging system with film or CR receivers as well as allowing the use of DR receivers.
(b) do not minimize the impact of the retrofit on system hardware. Regulatory requirements for x-ray equipment make it highly undesirable to tamper with internal circuitry or connections, such as those required for a number of retrofit solutions. Invasive reconfiguration of an x-ray control panel could void existing approvals or certifications of the equipment or could even be in violation of regulatory rules and restrictions in some cases.
(c) do not minimize changes to workflow and impact upon patient care. A suitable retrofit solution should add the new capabilities of DR imaging with as little impact as possible on existing practices for positioning the patient and for obtaining exposures.
Thus, while various retrofit solutions have been proposed, there remains a need for a DR retrofit that has little or no impact on existing hardware, is minimally invasive with respect to the components of an existing x-ray system, and does not constrain the system's ability to use earlier film and CR imaging media.